Protective guide device for well instruments



Sept. 8, 1953 n c. P. COLLINS ETAT. 2,651,199

PROTECTIVE GUIDE DEVICE FOR WELL INSTRUMENTS Filed Aug. 2, 194e EET Il\\\\1\ T\1 d 11 Cborle F. Colln Charles A. Brokaw Patented Sept. 8, 1953 vUNITED STATES PATENT OFFICE PROTECTIVE GUIDE DEVICE FOR WELL INSTRUMENTS Application August 2, 1946, Serial No. 687,838 2 Claims. (Cl. 73-151) This invention relates to new and useful improvements in protective guide devices for well instruments.

One object of the invention is to provide an improved device which is particularly adapted for use with the outer barrel or casing of a well instrument and which functions to guide and center said barrel or casing within the well pipe or bore as the same is lowered or raised therethrough, said device also functioning to protect the casing and instrument against undue shock or jar during the lowering and raising operations.

An important object of the invention is to provide an improved guide and protective assembly which includes a exible guide and centering element having longitudinally extending guide ribs or wings, said wings projecting outwardly from the body of the element and being disposed so as to be assembly .through the well bore or pipe.

A particular object of the invention is to provide an improved guide and protective assembly of the outer edges of the wings in their norma-l extended position.

The construction designed to carry out the invention will be hereinafter described together with other features of the invention.

The invention will be more readily understood and wherein:

Figure 1 is a view partly in section and partly in elevation showing the improved protective in a. drill collar,

Figure 2 is an enlarged, transverse, longitudinal section of the device,

Figure 3 is an enlarged horizontal cross-sectional view taken on the line 3`3 of Figure 1, and,

Figure 4 is an enlarged, horizontal, cross-secn tional view illustrating the exible guide element in position within a drill pipe.

In the drawings, the numeral lil designates a sential, that these parts be made integral with each other. The upper end of the body is formed with an u pstanding externally screw-threaded pin is disposed of said element.

bore, as will be explained.

In order to permit to lbe connected with ber of Wings or ribs 24 may be with the top of the threaded pin I3 of the body lll. Obviously, when the line I9 is connected to the ear 2l, said line may be employed to lower a drill pipe or well bore. assembly may and then may retrieving tool shoulder I8 to face.

A flexible guide and centering member 22 is mounted on the cylindrical mandrel Il and as is clearly shown in Figures 2 to 4, this member comprises a sleeve or body portion 23 having a plurality of outwardly extending ribs or wings 24 which are made integral therewith. The member 22 may be constructed of neoprene, rubber or other flex'ble material. Any desired numdisposed at equidistant points around the Sleeve portion 23 and each rib has the upper portion of its longitudinal edge inclined inwardly at 25, while the lower portion of said longitudinal edge is inclined inwardly as indicated at 26. The inclination or beveling of the upper and lower portion of the longitudinal edges of the wings or ribs 24 will facilitate movement of the member through a drill pipe and past the various irregularities or couplings which may be encountered in said pipe.

The disposition of the ribs or wings 24 with; respect to the center of the sleeve portion 23 and the mandrel Il is an important feature of the present invention. Obviously, since the member 22 is constructed of rubber or flexible material the ribs or wings have an inherent elasticity or resiliency. This inherent resiliency normally holds the wings or ribs in the position shown in Figure 4 in which position the longitudinal axis of each rib is disposed at an angle with respect to a radial line extending from the center of the sleeve portion 23 and mandrel Il. Each wing or rib 24 is disposed more toward a tangential position with respect to the sleeve portion 23 than toward a true radial position. This locates the wings 24 in an angular position with respect to a radial plane within the drill pipe with the result that any pressure imposed upon the wings will tend to move the wings inwardly toward a folded position around the tubular portion 23 of the member, as indicated in Figure 3. This arrangement permits the flexible member 22 to readily pass through diameters which are considerably smaller than the normal outside diameter of the outer edges of the wings or ribs when in a normal position.

The flexible member 22 is retained in position on the mandrel Il by a cylindrical adapter 21 which is threaded onto the lower end of the mandrel and which has its upper end engaging the lower end of the member 22. It will be evident that the flexible member 22 is conned between the adapter and the external shoulder l2 formed at the base of the body lll. When said member becomes worn and requires replacement it is only necessary to remove the adapter 21 to allow removal of the member 22 and replacement thereof by a new member.

The adapter 21 is formed with a downwardly extending connecting pin 28 which is adapted to thread into the upper end of an instrument barrel A. A well survey instrument B is housed within the barrel A and may be suitably protected against shock therein by coil springs C at each end of said instrument. A bull plug D closes the lower end of the barrel A. It is noted be retrieved by engaging a suitableV (not shown) with the undercut lift the assembly back to the survthat the barrel A may be of any desired construction, as may be the well instrument mount- 'ed therein,

In the running of well instruments, such as :survey instruments which measure the inclina- A'tion of a well bore, it is evident that the instrument should be centered within the drill pipe ysince the pipe naturally follows the same inclination as the well bore. The assembly, comprising fthe present invention, not only centers and guides the barrel A and well survey instrument contained therein but also functions as a shock absorber during the lowering and raising of the device through the well. It is pointed out that normally the drill pipe indicated at E has an 'elongate drill collar F connected to its lower end and below said drill collar, the drill bit (not shown) is attached. A landing plate G is usually ydisposed at the lower end of the drill collar F :and functions to arrest or stop the survey instrument assembly in position within the collar. The bore F of the drill collar is of a lesser vdiameter than the bore E' of the drill pipe.

In the use of the present apparatus, the assembly as shown in Figure 2 is connected through the adapter 21 with the usual well instrument barrel or outer casing. This disposes the flexible guide and centering member 22 immediately above the barrel or casing A. If the device is to be lowered by means of a wire line or cable i9, the line is threaded through the bore 20 of the upper element I5 and is connected to the ear or lug 2l of the body I0 and the assembly is then lowered through the drill pipe E. During such lowering, the wings or ribs 24 of the flexible guide member 22 are in a normal extended position, as shown in Figure 4 and there is preferably a slight clearance between the bore E' of the drill pipe and the outer longitudinal edges of the ribs or wings; this clearance, however, is only sufficient to permit free passage of the guide member so that no substantial misalignment can occur. If the guide wings 24 strike an obstruction or restriction in the drill pipe, the particular disposition of said wings with respect to a radial plane from the center of the mandrel il allows said wings to be moved or folded inwardly into an overlapping relation with respect to the body 23 so that in effect the outer diameter of the guide member is reduced to permit free passage thereof through the restriction. It is noted that because of the particular disposition of the wings toward substantially a tangential position with regard to the body portion 23, a true radial thrust is not imparted through the wings and 1t is this arrangement which allows a thrust on the outer end of each wing to cause said wing to move inwardly toward a folded position overlapping the body.

The assembly is lowered until the bull plug D on the instrument barrel A strikes the landing plate G within the lower end of the drill collar. As the assembly moves into the drill collar having a smaller bore than the drill pipe, the wings or ribs 24 of the flexible guide member are folded inwardly, as shown in Figure 3. This inward movement of the guide wings reduces the eiective diameter of the guide member 22 and provides for a proper centering of the member within the drill collar. Obviously, this centers the barrel A as well as the instrument contained therein within said collar so that an accurate recording can be made by said instrument. It is also apparent that during the lowering operation, the flexibility of the wings 24Yfunctions to absorb shock and jar has been operated. However, it may not be desirable in certain cases to employ the line I9 for lowering and raising said instrument and in such cases the line is completely omitted with the asner. The entire assembly is then dropped so as to fall into the drill collar by gravity or is pumped downwardly into position. After the instrument has been actuated and the assembly is to be removed, it is only necessary to lower a suitable retrieving or fishing tool (not shown) which may be engaged beneath Vthe undercut shoulder I 8 at the upper end of the retrieving element I5. The retrieving or fishing tool may then be lifted to raise the assembly to the surface in the usual manner.

It is pointed out that the device comprises a very simple and effective arrangement for guid- 1.

ing and centering a well instrument barrel or casing within a drill pipe or well bore. ible member 22 not only functions to guide and center the assembly but also acts as a shock absorber to prevent excessive or undue shocks and f jars being imparted to the well instrument during lowering and raising of the same within the well. The particular arrangement at the upper end of the assembly makes it possible to either employ a lowering line I9 for moving the assembly through the well bore or to godevil the assembly without the use of said line. Whether the assembly is lowered by a wire line or is merely pumped or go-deviled to bottom makes no difference since there is no change in construction ref quired to adapt the device to the different methods of lowering. The construction of the flexible member 22 is important since the particular disposition of the guide wings or ribs make it possible to accurately guide and center the assembly in passages of varying diameters. Because of the fact that the guide wings or ribs 24 may be folded or urged inwardly upon reaching a restricted diameter passage, the element functions to accurately guide and protect the assembly without in any manner interfering with the movement of the assembly through the well bore or drill pipe.

The flexible guide member 22 has been shown and described as mounted above the well instrument barrel but it is noted that if desired it could be attached or positioned below the barrel. As a matter of fact, in some'instances it might be desirable to provide two of the flexible guide members, one above and one below the barrel which would definitely assure proper guiding and centering of said barrel and its instrlunent within the drill pipe or well bore.

The foregoing description of the invention is explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made, within the scope of the appended claims, without departing from the spirit of the invention.

We claim:

1. A guide device and retrieving structure 70 adapted to be connected to the outer casing of a. well instrument as a unit and including, a suppasses to one side of the axis of the body. whereby any pressure on the outer edge portion of each guide wing will cause an inward movement of the guide wing toward a position overlapping the exterior of the body portion, an adapter coupling detachably connected to the lower end of the reduced portion and connecting the lower end of the support to the well instrument casing and also functioning to retain the guide member in position on the reduced portion of the support, a cable connecting means at the upper end of the support whereby a lowering cable may be connected therewith, and a retrieving head removably threaded onto the upper portion of the support and having an axial bore directly above the cable connecting means and through which a cable attached to the cable connecting means may extend, said retrieving head acting as a protector for the cable connecting means and making it possible to retrieve the device in the event a lowering cable is not employed.

CHARLES P. COLLINS. CHARLES A. BROKAW.

References Cited in the file of this patent UNITED STATES PATENTS 

